1. Field of the Invention
The present invention relates to a process for liquid cultivating Schizophyllum commune Fr. for isolation of .beta.-1,6-branched-.beta.-1,3-glucan and a composition for external application containing .beta.-1,6-branched-.beta.-1,3-glucan obtained by the same.
2. Description of the Prior Art
The skin has a protection function against the surrounding environments such as change of temperature or humidity, ultraviolet, pollution materials. However, the normal function of the skin may be depressed by the excessive physical or chemical stimulation and stresses, or nutrient deficiency, causing skin-aging and skin-damage. So, in the cosmetic filed, for keeping the skin beautiful and healthy by preventing this hypergasia, physiological active materials derived from animals, plants or microorganisms have been used as a cosmetic ingredient.
For example, it has been reported that extracts of fungi have a moisture retention ability, inhibition ability of melanin-formation and screening ability of ultraviolet and thereby can be incorporated in a cosmetic composition to impart skin-whitening effect or anti-oxidative action. In particular, an extract of Schizophyllum commune Fr. to impact excellent skin whitening activity and moisture retention effect has been disclosed in JP-5-286843A.
However, its active component has not been revealed yet. That is to say, what component of the extract of Schizophyllum commune Fr. can impart effective skin action needs further research to be revealed. Such a further research may include improvement in method for effective and pure isolation of active components.
Therefore, the present inventors have conducted extensive studies in order to reveal active components of the extract of Schizophyllum commune Fr. to impact effective skin action. As a result, they found that .beta.-1,6-branched-.beta.-1,3-glucan obtained by liquid cultivation of Schizophyllum commune Fr. can inhibit melanin-formation, promote biosynthesis of skin-cells and collagen, and cure burn caused by excessive sun exposure.
Further, they found that yield of .beta.-1,6-branched-.beta.-1,3-glucan may be increased by adding an activated charcoal or glucose into the liquid medium. They also found that the yield of .beta.-1,6-branched-.beta.-1,3-glucan can be more increased by adding both activated charcoal and glucose into the liquid medium.